Road screed



Dec. 3l, 1929. w. HELTZEL 1,741,459

ROAD SCREED Filed Sept. 17, 1927 2 sheets-sheet 1 HAN Dec. 3l, 1929. J.w. HELTzr-:L

ROAD S GREED Patented Dec. 31, 1929 Y A UNi'rE TATES PATENT ori-icsJOSEPH WILLIAM HELTZEL, F WARREN, OHIO ROAD scREED Application filedSeptember 17, 1927. Serial No. 220,284.

The present invention relates to concrete screed being broken away, andparts in rear road finishers or machines which are enibeing omitted forsake of clearness. Y ployed for finishing off the surface of a con- Fig.2 is a front View of the main screed, crete road under construction, andthe inven with the secondary screed removed.

tion has for an obj ect the provision of a novel Fig. 3 is a fragmentaryside elevation of the 55 and improved screeding or strike olf devicefinishing machine on an enlarged scale. by means of which the surface ofthe road F ig. 4 is a horizontal section on the line may be formed witha crown of desired mag- 4-4 of F ig. 3 on an enlarged scale. nitude ormay be made flat such as at turns Fig. 5 is a section on the line 5 5 ofFig. 4. or bends in the road. Fig. 6 is an enlarged section on the line6-6 60 Another object of the invention is the proof Fig. l through themain and secondary vision in a finishing machine of a main screedscreeds.

or strikeoff which is adapted to give the sur- Fig. 7 is a fragmentaryelevation of the face of the road the desired crown, in coinlever forflexing the secondary screed, showbination with a secondary screed orstrikeoff ing modifications. 65

that is adjustable for gradually decreasing Fig. 8 is a fragmentary viewillustrating the crown until the surface of the road is flat anothermodification in the control of the secand then gradually restoring thecrown, as ondary screed. the machine approaches and moves away The mainscreed or strikeoff comprises an from a bend or turn in the road. It isthe angle iron 11 with a forward upstanding 70 practice to crown theroad 0r to have the surflange and a lower rearwardly' extending facethereof conveXed transversely when the flange, and a plate l2 ofsuitable width on road is straight or substantially straight and whichthe lowei' flange of the angle iron is to have the surface fiat atcurves or turns in riveted, welded, or otherwise secured adjacent 5 theroad, with the road inclined transversely to the forward edge of saidplate. The angle and higher at the outer edge of the curve than iron andplate are of a length greater than at the inner edge, S0 that theutility of the `the width of theroad, so that the vplate'12 of presentinvention will be apparent.` j the screed is slidable on the side railsor 'Sion of a Secforms 18 which define the sides or edges of the Anotherobject is the provi l 0 Ondary screed of novel Construction t0 be asroadunder construction. Deflectors 14 are 80 senibled with a main screed foradjustment to SGCUTQ- t0 the @Ild pOFOIlS Of the angle IOIl decrease thecrown of the road until the sur- 1l ilbOW the lbllS 13 Ol CleflGCtlIlgthe maface of the road is flat, and vice versa, and tGIll inwardly.

attrait@entre that narrante naar 85 screed l y t i A loosely at theirforward ends with the angle V-lew Whlch Wm be appment asth-e'descmplonoitudilfially of itself transverseljgrofctleie 40 nonpoceedsthe mventmn resldes 1n the Conroal. The screed is reciprocated bvmeans of 90 dtructlon and arrangeme-nt of .part-stas here' a rock shaft17 having` an arm 18u connected mafter descrlbed and damned 1t heiligunder" by a link 19 with thebscreed and the screed sood that chailges.can be made Wlthm @he may be lifted off the road by ineans of chainsScope of ls Claimed Without depatmg or flexible elements 20 connectedtothe screed from the Spuit of .thi mventlon'. and to a transverse shaft21 mounted on the 95 The invention is illustrated in the accom- CarriageOr frame 16 for Winding the Chains panying drawings, whereinthereon AFigure l le a TOD View Of 2L COIlClet@ lOfLd The main screed abovedescribed is adjustfinisher having the improvements iIlCOrpO- able,being resilient so that it may be bowed 100 rated therein, a portion ofthe secondary Vor sprung upwardly intermediate its ends.

TSI

In order to adjust the screed to the desired crown of the road, a truss22 is secured at its ends to the angle iron 1l near opposite endsthereof, and an adjusting bolt or stay 23 is connected to the centralportion of the screed and passes upwardly slidably through the cen ralportion of the truss 22, and nuts 24 are threaded on said bolt above andbelow the truss. By adjusting the nuts 24 the central portion of thescreed may be raised and lowered to bend or bow the screed to thedesired crown or curvature.

The secondary screed or strikeoff is adapted for attachment to andremoval from the main screed, being a separate and distinct unitalthough when assembled with the main screed the two screeds cooperateone with the other. The secondary screed comprises an angle iron 25having a rear upstanding flange and a. lower forwardly extending flange.The rear flange bears rearwardly against the upstanding flange of theangle iron 11, as seen in Fig. 6. rlhe secondary screed also includes arearwardly inclined upwardly extending plate 26 having a rearwardlyextending flange 27 at its lower edge secured on the lower flange of theangle iron 25 by means of bolts 28, rivets or other securing elements.The angle iron 25 and plate 26 are resilient so as to be capable ofbeing sprung or bowed. The plate 2G being` inclined rearwardly willfacilitate the springing of said plate, and to further facilitatespringing` of said plate it may be formed with slits 29 and 30, as seenin 1Eig. l. The slits 29 extend upwardly from the lower edge of theplate 26 and through the flange 27 while the slits 30 extend downwardlyfrom the upper edge of the plate, said slits being in staggeredarrangement. Then the plate 26 is sprung upwardly between its ends theupper slits 30 open slightly and the lower slits 29 close, while thelower slits 29 open slightly and the upper slits 30 close when thesecondary screed is straightened out.

The secondary screed is disposed in front of the main screed between thedellectors 14, and the plate 26 will serve as a baffle to prevent theaggregate in front of the screeds from passing over the screeds.

In order to attach the secondary screed to the main screed, bolts 31 orother securing elements are carried by the angle iron 25 near the endsthereof and pass through horizontal slots 32 in the angle iron l1 of themain screed, thereby permitting the secondary screed to be sprungwithout interference.

The means for adjusting the secondary screed includes a lever 33extending from the fender of the machine to one side thereof andfulcrumed on a bracket 34 bolted or otherwise secured tothe truss 22 ofthe main screed. Said lever has a short inner arm connected by a link 35with the angle iron 25, whereby the long arm of the lever may be -adjusted upwardly and downwardly for bowing or straightening out thesecondary screed with considerable leverage.

In order to conveniently adjust the lever 33, a slotted post 36 issecured to the angle iron 25 at one end thereof, and a nut 37 isslidable vertically in said post and has a pin and slot connection 38 orother suitable connection with the lever 33. The nut 37 engages avertical screw 39 mounted in the post 36, and said screw has a handwheel 40 at its upper end whereby the screw beconveniently rotated toraise and lower the nut 27 and long arm of the lever 33.

When the machine is operating along a straight or substantially straightstretch of road, the secondary screed may be bowed or sprung upwardly sothat its lower surface (lower surface of the bottom flange of the angleiron 25) is flush with the lower surface of the plate l2, in order thatthe secondary screed will cooperate with the main screed for crowningthe surface of the road, although if desired the secondary screed may besprung higher than the plate 12. l/Vhen the machine is approaching acurve or bend in the road, the hand wheel 40 may be turned slowly or atintervals so as to gradually raise the long arm of the lever 33 anddepress the link 35 and intermediate portion of theV secondary 9 screed,in order that the crown of the road will be gradually reduced andeliminated until the secondary screed is straight to produce a flatsurface in the road at the bend or turn, and as the machine moves awayfrom the bend or turn the hand wheel 40 may be rotated in the oppositedirection to gradually spring the secondary screed upwardly and therebyrestore the crown. It is thus possible to manually adjust or set thesecondary screed to reduce and eliminate the ycrown and then graduallyrestore the same, for predetermined distances.

rlfhe adjustment of the secondary screen may also be accomplishedautomatically from a gear wheel 4l or other wheel or membery which isrotatable with the propelling mechanism ofthe machine. The gear wheel 4lmay be a part of the gearing which propels the machine, so that thewheel 4l rotates in accordance with the movement of the machine on theside rails. Therefore, by operably connecting the wheel 4l and screw 39,the secondary screed may be adjusted in ratio to the distance ofmovement of the screed. As shown, a pinion 42 meshes with the gear wheel41, and a shaft is slidable through said pinion and is rotatedtherewith.v A hand lever 44 is provided for sliding the shaft, and apair of bevel gears 43 are secured on said shaft 45 to mesh alternatelywith a bevel gear 47 secured on a exible shaft 46 which has a worm 48carried by the post 36 and meshing with a worm wheel 49 secured on thescrew 39 below the hand ist wheel 40. The shaft 46 has universal joints50 and a telescopic joint 5l to permit of flexibility, so that the screw39 may reciprocate with the screeds without disturbing the operativeconnection. By moving the hand lever 44 either bevel gear 43 may bebrought into mesh with the bevel gear 47, so that the screw 39 may berotated in either direction for raising or lowering the long arm of thelever 33. It is thus possible to gradually straighten out and then bowthe secondary screed through predetermined distances of movement of themachine when approaching and leaving a bend or turn in the road withoutrequiring manual adjustment, other than the making and breaking` of theconnections between the driving member of the machine and the screw 39.If manual adjustment is desired the worm 48 or worm wheel 49 may beloosened so as not to interfere with the rotation of the screw 39 by thehand wheel 40.

The screeds are made of metal, and the main screed is fairly rigid, soas to be substantial when sprung to different curvatures, while thesecondary screed is more freely bendable to be quickly bent fromfull-crown to straight position and vice versa.

In some cases the secondary or front screed may be bowed slightly higherthan the rear or main screed, so that the intermediate portion thereofis one-eighth of an inch (more or less) higher than the intermediateportion of the main screed. The front or secondary screed will thenfinish the surface slightly higher than intended, and the main screedfollowing will finish off' the surface to the desired crown, and thematerial or aggregate will be smoothed out so as to eliminate all voidsand thus produce a smoother surface or finish.

Fig. 7 shows the lever 33 corresponding with the lever 33 abovedescribed, projecting through the post 36 and provided with a handle 40for swinging said lever, and the lever may be held in various positionsby means of a pin 37 inserted through apertures in the lever and post,whereby the secondary screed may be maintained in different flexedpositions. By swinging the lever the secondary screed may be bentupwardly and downwardly, and the lever may be changed by removing andinserting the pin 37 as the machine moves predetermined distances.

Fig. 8 illustrates another modification in the means for controlling thesecondary screed. Thus, a nut 37 is carried by the truss 22 of the mainscreed, and a vertical screw 39 is threaded through said nut and has ahand wheel 40 at its upper end for conveniently rotating said screw. Thelower end of the screw has a swivel connection 35 with the secondaryscreed, in order that the secondary screed may be conveniently bentupwardly and downwardly, said screw being located at the center of themachine.

Having thus described the invention, what is claimed as new is 1. Asecondary screed comprising an angle iron having a rear upstandingflange for attachment to the main screed of a. concrete road finishingmachine and having a lower forwardly extending flange, and an upwardlyextending plate secured on said lower flange.

2. A concrete road finishing machine including a member operable in thepropelling of the machine, an adjustable screed, and an operativeconnection between said screed and member for adjusting the screed asthe machine is moved.

3. A concrete road finishing machine having a member movable as themachine is propelled, a main screed, a secondary adjustable screedmovable from crown to straight position and vice versa, and an operativeconnection between the secondary screed and said member for adjustingthe secondary screed in either direction in the movement of the machine.

4. A concrete road finishing machine having a member operable by thepropelling of the machine, a main screed, a secondary screed having itsend portions connected with the main screed, and an operative connectionbetween the intermediate portion of the secondary screed and said memberfor s ringing the secondary screed either upwar ly or downwardly by themovement of the machine.

5. A screed including an upwardly extending sheet metal plate havingslits extending from its upper and lower edges and in staggeredarrangement.

In testimony whereof I hereunto afiix my signature.

JOSEPH WILLIAM HELTZEL.

